Accuracy: ?2″.
To inspect protractor, taper gage, index plate, index head and goniometer, can also be used to set angle.
Made of special alloy steel, hardness HRC64, high stability, wear resistance and easy combination.
Can be combined to any angle with interval 6 seconds after combination (6″, 12″, 18″, … , 360?).

Insize 4112-BD132, INDIVIDUAL STEEL GAGE BLOCK, .132", grade AS-1, 6928640352751
Dynabrade 95676 1/4" Female Coupler with 1/4" Male Plug Assembly
3M 07053, General Purpose Sanding Sponge CP040-12-CC, Single Angle, 2-7/8 in x 4-7/8 in x 1 in, Fine, 7100101245 